As you start to prepare for Fantasy Football drafts, we examine running backs to draft cautiously. All of them have the skills and experience to be top ballcarriers, but with injury concerns their season could also turn into a huge bust.

Only take one or two of these guys on your roster, and don’t reach and take them too early. Also have a solid backup in case they do get re-injured or consider handcuffing the higher-round guys.

Adrian Peterson, New Orleans Saints: Peterson is coming off of a lost season where he had surgery to repair a torn meniscus and then suffered a groin injury because he came back to soon. He has long been one of the league’s best backs, but at 32 his age and injuries make him a tough player to predict.

Through multiple knee injuries (including a 2011 torn ACL), Peterson proved that he can recover much faster than the average NFL player, but it cost him last season by coming back too soon. He had a normal offseason and is healthy heading into 2017.

The one thing that could help Peterson is his role with the Saints. Paired with Mark Ingram, Peterson won’t have to carry the load and put as much stress on his body. This does hurt his fantasy value because he will be splitting carries, but it also could lead to better long-term results because he will be fresher late in the year.

Lamar Miller, Houston Texans: Miller is lined up for a big role in, even with the addition of third-round pick D’Onta Foreman. But Miller missed the final two games of last season with an ankle sprain and played through some nagging injuries late in the year. He’s healthy now and his Injury risk is improving, but he’s not there yet.

The Texans overused Miller early in the year as he had 268 carries, by far a career-high for him. He is a running back who performs better when he has fewer touches, and it will only help his durability if Foreman can be a contributor.

Marshawn Lynch, Oakland Raiders: After a season off due to “retirement,” Beast Mode is back. But why isn’t he a “Low Injury Risk” after a year to rest and get healthy? Well, there are quite a few factors to consider here. First is his age. He’s a 31-year-old running back with 10 years in the league. That’s a lot of wear and tear, especially for a guy with over 2,000 career carries. Then there are his injuries to consider. He was banged up in 2015, and that included sports hernia surgery, a hamstring strain and a calf injury. Don’t forget about his chronic back issues, too. They weren’t a huge factor in 2015, but they can come back at any moment.

Sure, Beast Mode has been one of the league’s most bruising runners over the last decade, and he’s joining a promising offense, but there are far too many red flags here.

Lynch has high upside when he’s on the field but a very low floor due to the likelihood that he will miss time. Oakland’s strong passing game could also hurt his usage, and if he gets under 200 carries this season for whatever reason that would lead to a drop in value.

Eddie Lacy, Seattle Seahawks: Lacy won’t be handed the starting job, but he is first in line to win the spot. Lacy is coming off of season-ending ankle surgery and will have to fight Thomas Rawls and C.J. Prosise for touches. He is past the 16 week Optimal Recovery Time following his surgery but remains an Elevated Injury Risk. Using an early round pick on a guy with injury and playing time concerns is risky.

Lacy does have a history of playing through quite a few bumps and bruises, but he missed just two games before the ankle injury ended his 2016 season. If Lacy proves he is healthy at training camp and his ankle is fully recovered, his numbers should improve. Getting that burst back following surgery is critical for a running back. We haven’t seen much from him yet, so it’s fair to assume his recovery is ongoing. He’s one to watch closely this month.

Le’Veon Bell, Pittsburgh Steelers: Bell is battling David Johnson for the top spot in fantasy drafts, but comes with a greater risk. When healthy Bell is the most explosive, dangerous running back in the league, but he has played just 18 games in the last two seasons due to injuries and suspension. He has had multiple left knee injuries, including a serious MCL sprain in 2015, and he suffered a groin injury late in 2016 that required surgery.

One of the problems the Steelers may need to address to keep Bell on the field is his workload. He was responsible for 86% of his team’s carries last season and 22% of the targets. Yes, a lot of his injuries are unavoidable, but he does need more time to rest and recover. Bell is holding out for now, but he needs to make sure he gets in enough work so he is ready for the season. He also needs to test out his body following core muscle surgery in March.

DeMarco Murray, Tennessee Titans: Murray underwent surgery in early June on his ring finger and has already fully recovered. He has also missed just one game in the last three seasons, so why is he a guy to draft cautiously? 2016 was a bounce-back year for Murray following a disappointing 2015 campaign with his new team, but a torn plantar plate is cause for concern. He also has had past foot problems.

Murray may be feeling good, although there are quite a few things to keep an eye on. He needs to test out his foot to ensure that it really has fully recovered. Foot and toe injuries have a tendency to recur, and this could be a serious problem if it isn’t healed. His finger, while a relatively minor concern, will have an impact on his ball security.

Mark Ingram, New Orleans Saints: The addition of Peterson was one of the biggest offseason moves, and it has a major impact on Ingram. In the past, Ingram has been the unquestioned workhorse in New Orleans. Now, he will fight for carries as he shares the backfield with Peterson.

This is a good and a bad thing. It’s a good thing because he needs the help and will stay fresher if he isn’t approaching 25 touches most games. Ingram has a lengthy injury history, and adding another strong runner will take some of the pressure off. Of course the addition of Peterson also hurts because it’s turned this into a messy, unpredictable backfield.

Carlos Hyde, San Francisco 49ers: In Hyde’s three years in the league, he has amassed a lengthy list of injuries. In 2014 it was a back injury that forced him to miss the final two games of the regular season. In 2015 he played just seven games because of a foot fracture that ended his season, and in 2016 he suffered a preseason concussion, missed one game with an MCL sprain and missed two games with a shoulder sprain.

Hyde is a quick, natural runner, especially impressive due to his size, but injuries have kept him from being one of the top backs in the league. He hopes to change all that this season, but he will have to stay on the field long enough to make that happen.

Ameer Abdullah/Theo Riddick, Detroit Lions: Abdullah and Riddick are two young, exciting running backs for the Lions, but both have injury concerns. Abdullah suffered a mysterious foot injury in Week 2 and didn’t play the rest of the season. The team finally admitted that it was the dreaded Lisfranc tear. He has had plenty of time to recover, but this is a problem that can come with lingering effects. Foot injuries are especially tough on receivers and running backs, so monitor his progress and participation throughout training camp.

Riddick had a more successful season than Abdullah, but he played just 10 games and missed the final four games of the season with a wrist injury. During the offseason the team revealed that he underwent surgery on both wrists. He has a lot to prove as he recovers from two serious surgeries. He also wants to be more involved in the passing game, which would help his fantasy value, but with multiple wrist injuries he faces a tougher road ahead.

This is a messy backfield situation, and whichever guy comes out healthier could be the one with the edge. We just don’t know who that will be yet.